I kind of drifted from this thread, but long story short, here is what I did over a few weeks span:
1. PCS Mod:
Copied and pasted from a while back in my VSR project thread:
http://www.c3airsoft.com/showthread.php/vsr-10-project-thread-25460p2.html
Round One:
To start off the morning, I installed the PCS and put the rifle together, noticing a significantly large bulge inside of the rifle. It was slightly crooked but I decided to give it a whirl anyways. Keep in mind, the shim on the arm is still installed, so expect HUGEEE hop or jam right away.
Now with that said, keep in mind, I don't exactly have the luck of the irish, and my four leaf clover is still in my jeans from yesterday, so I was on my own for this one. Went outside, took a shot, and guess what...? Jam..
Round Two:
Decided to do a bit more filing, nothing too significant. Then I removed the shim on the hop up arm. With the PCS, getting hop is not a problem. So no need for extra hop up due to a shim on the arm. With that removed, much easier to install pieces on top/inside gap on arm.
Went out for a test shot, using .3s, and about 15-20% hop up on. The bb flew up a good 60 feet in the air. Very very large amount of hop on that one. I didn't even bother adjusting the hop up for .3s, as it was time to get the big boys out.
Got out the ol' madbull .4s, and gave her a go. Took some shots, with about 10% hop up on, and they're flying. A tad bit curve to the left but not near as bad of a curve as before, where you could literally hit a guy hiding behind a tree...
Overall: Ended up getting too much hop to handle .4s, and despite straight shots, they curved up way too much from all the hop.
In conclusion, the PCS mod=fail
Test Number 2:
So I decided to try using an o-ring instead of a nub. I took a small o-ring and placed it on the shaved down arm. Took some shots, not enough hop.
Then decided to use Mike's arm. I shaved it down just a tad, enough so that the ring could sit on top and not fall off (before the fangs were sanded down, they were like tips, no where for the ring to sit). Took some shots, and was carrying .4s on 5% hop up setting. I managed to get it shooting pretty nicely, enough to play a few games.
Something I am looking into doing is shaving the arms a bit more down, so that I can use .3s as well. By sanding the arm, that will give less hop. That means I can then use lighter bbs, and still use the heavy weights by simply adjusting the hop up for a higher setting.
This worked out perfectly, and I am still using this method to this day.